The Department of Chemistry at Harvard University requests funds for the acquisition of two mass spectrometers. The first will be a high-performance, high-resolution mass spectrometer with electron impact (EI), chemical ionization, (CI) and fast atom bombardment (FAB) ionization capabilities; this instrument will be operated by trained operators. The second will be a general purpose instrument open to use by all qualified users. A core group of six faculty and their research teams will use these new instruments to characterize complex organic compounds. Research conducted by this group includes the synthesis of biologically active substances (such as prostaglandins, leukotrienes, thromboxanes, blood group substances, immunostimulators, antibiotics, antiviral agents, polypeptides, sugars, hormones and nucleic acids) and the determination of structures of natural products and synthetic intermediates.